The princes in the tower were brothers: Edward V, aged 12, and Richard of Shrewsbury, Duke of York, aged nine. They were the only sons of Edward IV alive at the time of their father’s death. When Edward IV died suddenly on 9 April 1483, his son Edward was proclaimed king at Ludlow; his uncle – Richard, Duke of Gloucester – was named lord protector. Richard lodged Edward in the Tower of London, supposedly in preparation for his coronation; his brother joined him in June 1483, when there were reports of them playing in the grounds of the tower.

Shortly afterwards, the princes were declared illegitimate by an act of parliament, on the grounds that their father had been contracted to marry someone else before his marriage to their mother, Elizabeth Woodville. Their uncle was crowned King Richard III of England in July, and his two nephews were never seen again. It is widely assumed that they were murdered.

Shakespeare notably made the Tudor case for Richard as the prime suspect. Others, however, have claimed that Henry VII, also known as Henry Tudor, was responsible, or have pointed the finger of suspicion at Richard’s cousin Henry, Duke of Buckingham.

In 1674 the skeletons of two children were discovered in a wooden casket under a stone staircase connecting the royal apartments with the White Tower during building work at the Tower of London. On the orders of Charles II the remains, which were assumed to be of the two princes because the location matched a description by the Tudor historian Sir Thomas More, were reburied in Westminster Abbey.

The 17th-century Latin inscription with their reinterred remains, which are in bags in a sarcophagus designed by Sir Christopher Wren, reads: “These brothers being confined to the Tower of London and there stifled with pillows, were privately and meanly buried, by the order of their perfidious uncle, Richard the Usurper.”

In 1933 Westminster Abbey and King George V gave permission for the remains to be examined to see whether modern science could cast any light on the issues. The skeletons were and determined to be those of two young children, one aged seven to 11 and the other 11 to 13. However, photographs taken at the time failed to resolve the mystery surrounding their deaths – including the key question of who was responsible for them.

• This article was amended on 6 February 2013. The original gave the date of Edward IV’s death as 1493 rather than 1483. This has been corrected.